Antwerp, 27 June 1586. De Castro signed his Livre de chansons à cinq parties, which he addressed to Johann Wilhelm, Duke of Jülich, Cleves and Berg. Thus, by 1586 De Castro had returned to the Low Countries from his journey through Germany and France. However, it is not known exactly when De Castro has left Lyons to come back home.
He may still have been abroad in 1582: although in that year two volumes with his music appeared in Antwerp at the Phalèse-Bellère printing office, neither collection had a dedication nor contained new music (see Table IV nrs. 10 and 11), which suggests that 'pirate' editions are concerned here, produced at the instance of the printers in the absence of the composer, who was apparently still in France.
In 1585 the Spanish commander Alexander Farnese definitively conquered the Protestant rebels in Antwerp (see triumph column). The whole city re-entered absolute Spanish surveillance. A period of relative peace began, which may have encouraged De Castro to return home.
De Castro's Livre de chansons à cinq parties, signed in Antwerp on 27 June 1586, contains French chansons for five voices and is dedicated to Johann Wilhelm, Duke of Jülich, Cleves and Berg. The book opens with a nuptial song for Johann Wilhelm and Jakoba von Baden who were married in Düsseldorf in 1585.
The preface learns that the hymeneal "Viens doux Hymenée" was performed during the wedding banquet:"la Chanson ... fut chantée & célébrée au jour solemnel du riche impéral banquet de ses nopces" ("the Chanson ... was sung and celebrated on the solemn day of the rich imperial banquet of his wedding").
To advertise this honour which had fallen to his share, and to express his gratitude towards the Duke, De Castro decided to dedicate a whole music book to the Duke. Back in Antwerp, he compiled a new volume, included the hymeneal for Johann Wilhelm, had it published at the Phalèse-Bellère firm and wrote a dedication to the German Duke:"désirant faire cognoistre au monde, qu'il m'a esté permist d'estre du nombre de ses Serviteurs, je supplie Vostre Altesse treshumblement; reçevoir ce dit mien petit labeur en sa protection, comme tesmoignage de mon service et affection" ("Desiring to let the world know that I have been allowed to be among the number of His servants, I humbly request His Majesty to accept this little work of mine and keep it under his protection, as a witness of my service and affection").
Undoubtedly he aspired to a position at the music chapel of the Düsseldorf Court; a successful aspiration, since in 1588 he actually entered the Duke's service.